scholarly journals Transcriptome-Wide Analysis and Functional Verification of RING-Type Ubiquitin Ligase Involved in Tea Plant Stress Resistance

2021 ◽  
Vol 12 ◽  
Author(s):  
Dawei Xing ◽  
Tongtong Li ◽  
Guoliang Ma ◽  
Haixiang Ruan ◽  
Liping Gao ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Plant Stress ◽  
Ring Finger ◽  
Degradation Pathway ◽  
Tea Plant ◽  
26S Proteasome ◽  
Functional Verification ◽  
Proteasome Pathway ◽  
Tea Plants

The ubiquitin/26S proteasome pathway is a critical protein-degradation pathway in plant growth and development as well as in nearly all biological and abiotic stress processes. Although as a member of the ubiquitin/26S proteasome pathway, the E3 ubiquitin ligase family has been shown to be essential for the selective degradation of downstream target proteins, it has been rarely reported in tea plants (Camellia sinensis). In this study, through database searches and extensive manual deduplication, 335 RING finger family proteins were selected from the Tea Plant Information Archive. These proteins were divided into six categories by the difference of RING finger domain: RING-H2, RING-HCa, RING-HCb, RING-C2, RING-v, and RING-G. Stress-induced differential gene expression analysis showed that 53 proteins in RING finger family can respond to selected exogenous stress. In vitro ubiquitination assays indicated that TEA031033, which was named CsMIEL1, exhibited the activity of E3 ubiquitin ligases. CsMIEL1-overexpressing transgenic Arabidopsis thaliana seedlings were resistant to some exogenous abiotic stresses, such as salt and drought stress but sensitive to exogenous methyl jasmonate treatment. Furthermore, CsMIEL1 reduced the accumulation of anthocyanin in transgenic plants in response to low temperature treatment. The results of this article provide basic date for studying the role of ubiquitin/26S proteasome pathway in tea plants response to stresses.

scholarly journals Functional Analyses of Flavonol Synthase Genes From Camellia sinensis Reveal Their Roles in Anther Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Yufeng Shi ◽  
Xiaolan Jiang ◽  
Linbo Chen ◽  
Wei-Wei Li ◽  
Sanyan Lai ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Reproductive Organs ◽  
Tea Plant ◽  
Functional Verification ◽  
Metabolic Characteristics ◽  
Metabolic Properties ◽  
Tea Plants ◽  
Functional Analyses

Flavonoids, including flavonol derivatives, are the main astringent compounds of tea and are beneficial to human health. Many researches have been conducted to comprehensively identify and characterize the phenolic compounds in the tea plant. However, the biological function of tea flavonoids is not yet understood, especially those accumulated in floral organs. In this study, the metabolic characteristics of phenolic compounds in different developmental stages of flower buds and various parts of the tea flower were investigated by using metabolomic and transcriptomic analyses. Targeted metabolomic analysis revealed varying accumulation patterns of different phenolic polyphenol compounds during flowering; moreover, the content of flavonol compounds gradually increased as the flowers opened. Petals and stamens were the main sites of flavone and flavonol accumulation. Compared with those of fertile flowers, the content of certain flavonols, such as kaempferol derivatives, in anthers of hybrid sterile flowers was significantly low. Transcriptomic analysis revealed different expression patterns of genes in the same gene family in tea flowers. The CsFLSb gene was significantly increased during flowering and was highly expressed in anthers. Compared with fertile flowers, CsFLSb was significantly downregulated in sterile flowers. Further functional verification of the three CsFLS genes indicated that CsFLSb caused an increase in flavonol content in transgenic tobacco flowers and that CsFLSa acted in leaves. Taken together, this study highlighted the metabolic properties of phenolic compounds in tea flowers and determined how the three CsFLS genes have different functions in the vegetative and reproductive organs of tea plants. Furthermore, CsFLSb could regulated flavonol biosynthesis in tea flowers, thus influencing fertility. This research is of great significance for balancing the reproductive growth and vegetative growth of tea plants.

scholarly journals E6AP Ubiquitin Ligase Mediates Ubiquitylation and Degradation of Hepatitis C Virus Core Protein

2006 ◽  
Vol 81 (3) ◽  
pp. 1174-1185 ◽  
Author(s):  
Masayuki Shirakura ◽  
Kyoko Murakami ◽  
Tohru Ichimura ◽  
Ryosuke Suzuki ◽  
Tetsu Shimoji ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Core Protein ◽  
Protein Levels ◽  
The Core ◽  
Hcv Core Protein ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Viral Nucleocapsid

ABSTRACT Hepatitis C virus (HCV) core protein is a major component of viral nucleocapsid and a multifunctional protein involved in viral pathogenesis and hepatocarcinogenesis. We previously showed that the HCV core protein is degraded through the ubiquitin-proteasome pathway. However, the molecular machinery for core ubiquitylation is unknown. Using tandem affinity purification, we identified the ubiquitin ligase E6AP as an HCV core-binding protein. E6AP was found to bind to the core protein in vitro and in vivo and promote its degradation in hepatic and nonhepatic cells. Knockdown of endogenous E6AP by RNA interference increased the HCV core protein level. In vitro and in vivo ubiquitylation assays showed that E6AP promotes ubiquitylation of the core protein. Exogenous expression of E6AP decreased intracellular core protein levels and supernatant HCV infectivity titers in the HCV JFH1-infected Huh-7 cells. Furthermore, knockdown of endogenous E6AP by RNA interference increased intracellular core protein levels and supernatant HCV infectivity titers in the HCV JFH1-infected cells. Taken together, our results provide evidence that E6AP mediates ubiquitylation and degradation of HCV core protein. We propose that the E6AP-mediated ubiquitin-proteasome pathway may affect the production of HCV particles through controlling the amounts of viral nucleocapsid protein.

scholarly journals The APC11 RING-H2 Finger Mediates E2-Dependent Ubiquitination

2000 ◽  
Vol 11 (7) ◽  
pp. 2315-2325 ◽  
Author(s):  
Joel D. Leverson ◽  
Claudio A.P. Joazeiro ◽  
Andrew M. Page ◽  
Han-kuei Huang ◽  
Philip Hieter ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
26S Proteasome ◽  
Anaphase Promoting Complex ◽  
Mitotic Progression ◽  
Protein Substrates ◽  
Ubiquitin Ligase Activity ◽  
Ubiquitin Conjugating Enzyme ◽  
Ubiquitin Conjugating Enzymes

Polyubiquitination marks proteins for degradation by the 26S proteasome and is carried out by a cascade of enzymes that includes ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s). The anaphase-promoting complex or cyclosome (APC/C) comprises a multisubunit ubiquitin ligase that mediates mitotic progression. Here, we provide evidence that theSaccharomyces cerevisiae RING-H2 finger protein Apc11 defines the minimal ubiquitin ligase activity of the APC. We found that the integrity of the Apc11p RING-H2 finger was essential for budding yeast cell viability, Using purified, recombinant proteins we showed that Apc11p interacted directly with the Ubc4 ubiquitin conjugating enzyme (E2). Furthermore, purified Apc11p was capable of mediating E1- and E2-dependent ubiquitination of protein substrates, including Clb2p, in vitro. The ability of Apc11p to act as an E3 was dependent on the integrity of the RING-H2 finger, but did not require the presence of the cullin-like APC subunit Apc2p. We suggest that Apc11p is responsible for recruiting E2s to the APC and for mediating the subsequent transfer of ubiquitin to APC substrates in vivo.

scholarly journals The multiubiquitin-chain-binding protein Mcb1 is a component of the 26S proteasome in Saccharomyces cerevisiae and plays a nonessential, substrate-specific role in protein turnover.

1996 ◽  
Vol 16 (11) ◽  
pp. 6020-6028 ◽  
Author(s):  
S van Nocker ◽  
S Sadis ◽  
D M Rubin ◽  
M Glickman ◽  
H Fu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Binding Protein ◽  
Degradation Pathway ◽  
26S Proteasome ◽  
Wild Type ◽  
Cell Extracts ◽  
Steady State Levels ◽  
Type Rate ◽  
Beta Galactosidase

The 26S proteasome is an essential proteolytic complex that is responsible for degrading proteins conjugated with ubiquitin. It has been proposed that the recognition of substrates by the 26S proteasome is mediated by a multiubiquitin-chain-binding protein that has previously been characterized in both plants and animals. In this study, we identified a Saccharomyces cerevisiae homolog of this protein, designated Mcb1. Mcb1 copurified with the 26S proteasome in both conventional and nickel chelate chromatography. In addition, a significant fraction of Mcb1 in cell extracts was present in a low-molecular-mass form free of the 26S complex. Recombinant Mcb1 protein bound multiubiquitin chains in vitro and, like its plant and animal counterparts, exhibited a binding preference for longer chains. Surprisingly, (delta)mcb1 deletion mutants were viable, grew at near-wild-type rates, degraded the bulk of short-lived proteins normally, and were not sensitive to UV radiation or heat stress. These data indicate that Mcb1 is not an essential component of the ubiquitin-proteasome pathway in S.cerevisiae. However, the (delta)mcb1 mutant exhibited a modest sensitivity to amino acid analogs and had increased steady-state levels of ubiquitin-protein conjugates. Whereas the N-end rule substrate, Arg-beta-galactosidase, was degraded at the wild-type rate in the (delta)mcb1 strain, the ubiquitin fusion degradation pathway substrate, ubiquitin-Pro-beta-galactosidase, was markedly stabilized. Collectively, these data suggest that Mcb1 is not the sole factor involved in ubiquitin recognition by the 26S proteasome and that Mcb1 may interact with only a subset of ubiquitinated substrates.

scholarly journals The CUL1 C-Terminal Sequence and ROC1 Are Required for Efficient Nuclear Accumulation, NEDD8 Modification, and Ubiquitin Ligase Activity of CUL1

2000 ◽  
Vol 20 (21) ◽  
pp. 8185-8197 ◽  
Author(s):  
Manabu Furukawa ◽  
Yanping Zhang ◽  
Joseph McCarville ◽  
Tomohiko Ohta ◽  
Yue Xiong
Keyword(s):  
Nuclear Localization ◽  
Ubiquitin Ligase ◽  
Nuclear Import ◽  
Ring Finger ◽  
Nuclear Accumulation ◽  
Protein Families ◽  
Terminal Sequence ◽  
Ubiquitin Ligase Activity

ABSTRACT Members of the cullin and RING finger ROC protein families form heterodimeric complexes to constitute a potentially large number of distinct E3 ubiquitin ligases. We report here that the highly conserved C-terminal sequence in CUL1 is dually required, both for nuclear localization and for modification by NEDD8. Disruption of ROC1 binding impaired nuclear accumulation of CUL1 and decreased NEDD8 modification in vivo but had no effect on NEDD8 modification of CUL1 in vitro, suggesting that ROC1 promotes CUL1 nuclear accumulation to facilitate its NEDD8 modification. Disruption of NEDD8 binding had no effect on ROC1 binding, nor did it affect nuclear localization of CUL1, suggesting that nuclear localization and NEDD8 modification of CUL1 are two separable steps, with nuclear import preceding and required for NEDD8 modification. Disrupting NEDD8 modification diminishes the IκBα ubiquitin ligase activity of CUL1. These results identify a pathway for regulation of CUL1 activity—ROC1 and the CUL1 C-terminal sequence collaboratively mediate nuclear accumulation and NEDD8 modification, facilitating assembly of active CUL1 ubiquitin ligase. This pathway may be commonly utilized for the assembly of other cullin ligases.

scholarly journals Gp78 Cooperates with RMA1 in Endoplasmic Reticulum-associated Degradation of CFTRΔF508

2008 ◽  
Vol 19 (4) ◽  
pp. 1328-1336 ◽  
Author(s):  
Daisuke Morito ◽  
Kazuyoshi Hirao ◽  
Yukako Oda ◽  
Nobuko Hosokawa ◽  
Fuminori Tokunaga ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Ubiquitin Ligase ◽  
Yeast Cells ◽  
Glutathione S Transferase ◽  
Assembly Factor ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Membrane Spanning ◽  
Interfering Rna

Misfolded or improperly assembled proteins in the endoplasmic reticulum (ER) are exported into the cytosol and degraded via the ubiquitin–proteasome pathway, a process termed ER-associated degradation (ERAD). Saccharomyces cerevisiae Hrd1p/Der3p is an ER membrane-spanning ubiquitin ligase that participates in ERAD of the cystic fibrosis transmembrane conductance regulator (CFTR) when CFTR is exogenously expressed in yeast cells. Two mammalian orthologues of yeast Hrd1p/Der3p, gp78 and HRD1, have been reported. Here, we demonstrate that gp78, but not HRD1, participates in ERAD of the CFTR mutant CFTRΔF508, by specifically promoting ubiquitylation of CFTRΔF508. Domain swapping experiments and deletion analysis revealed that gp78 binds to CFTRΔF508 through its ubiquitin binding region, the so-called coupling of ubiquitin to ER degradation (CUE) domain. Gp78 polyubiquitylated in vitro an N-terminal ubiquitin-glutathione-S-transferase (GST)-fusion protein, but not GST alone. This suggests that gp78 recognizes the ubiquitin that is already conjugated to CFTRΔF508 and catalyzes further polyubiquitylation of CFTRΔF508 in a manner similar to that of a multiubiquitin chain assembly factor (E4). Furthermore, we revealed by small interfering RNA methods that the ubiquitin ligase RMA1 functioned as an E3 enzyme upstream of gp78. Our data demonstrates that gp78 cooperates with RMA1 with E4-like activity in the ERAD of CFTRΔF508.

Wheat RING E3 ubiquitin ligase TaDIS1 degrade TaSTP via the 26S proteasome pathway

Plant Science ◽  
2020 ◽  
Vol 296 ◽  
pp. 110494
Author(s):  
Qian Lv ◽  
Li Zhang ◽  
Ting Zan ◽  
Liqun Li ◽  
Xuejun Li
Keyword(s):  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
26S Proteasome ◽  
Proteasome Pathway ◽  
Ring E3

scholarly journals Diversity of Pestalotiopsis-Like Species Causing Gray Blight Disease of Tea Plants (Camellia sinensis) in China, Including two Novel Pestalotiopsis Species, and Analysis of Their Pathogenicity

Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2548-2558 ◽  
Author(s):  
Yuchun Wang ◽  
Fei Xiong ◽  
Qinhua Lu ◽  
Xinyuan Hao ◽  
Mengxia Zheng ◽  
...  
Keyword(s):  
Geographical Distribution ◽  
Mycelial Growth ◽  
Elongation Factor ◽  
Tea Plant ◽  
Translation Elongation ◽  
Pathogenicity Tests ◽  
Tea Production ◽  
Tea Plants ◽  
Blight Disease

Several Pestalotiopsis-like species cause gray blight disease in tea plants, resulting in severe tea production losses. However, systematic and comprehensive research on the diversity, geographical distribution, and pathogenicity of pathogenic species associated with tea plants in China is limited. In this study, 168 Pestalotiopsis-like isolates were obtained from diseased tea plant leaves from 13 primary tea-producing provinces and cities in China. Based on a multilocus (internal transcribed spacer, translation elongation factor 1-α, and β-tubulin gene region) phylogenetic analysis coupled with an assessment of conidial characteristics, 20 Neopestalotiopsis unclassified isolates, seven Pestalotiopsis species, including two novel (Pestalotiopsis menhaiensis and Pestalotiopsis sichuanensis), four known (Pestalotiopsis camelliae, Pestalotiopsis chamaeropis, Pestalotiopsis kenyana, and Pestalotiopsis rhodomyrtus) and one indistinguishable species, and three Pseudopestalotiopsis species, including two known (Pseudopestalotiopsis camelliae-sinensis and Pseudopestalotiopsis chinensis) and one indistinguishable species, were identified. This study is the first to evaluate Pestalotiopsis chamaeropis on tea plants in China. The geographical distribution and pathogenicity tests showed Pseudopestalotiopsis camelliae-sinensis to be the dominant cause of gray blight of tea plants in China. In vitro antifungal assays demonstrated that theobromine not only derepressed mycelial growth of the 29 representative isolates but also increased their growth. Correlation analysis revealed a linear positive relationship between the mycelial growth rate and pathogenicity (P = 0.0148).

scholarly journals Proteasome pathway operates for the degradation of ornithine decarboxylase in intact cells

1996 ◽  
Vol 317 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Yasuko MURAKAMI ◽  
Nobuyuki TANAHASHI ◽  
Keiji TANAKA ◽  
Satoshi ŌMURA ◽  
Shin-ichi HAYASHI
Keyword(s):  
Ornithine Decarboxylase ◽  
Proteasome Inhibitor ◽  
Mammalian Cells ◽  
Degradation Pathway ◽  
Dependent Manner ◽  
Intact Cells ◽  
Htc Cells ◽  
Proteasome Pathway ◽  
Hypertonic Shock

Ornithine decarboxylase (ODC) is degraded in an ATP-dependent manner in vitro by the 26 S proteasome in the presence of antizyme, an ODC destabilizing protein induced by polyamines. In the present study we examined whether the proteasome catalyses ODC degradation in living mammalian cells. Lactacystin, the most selective proteasome inhibitor, strongly inhibited the degradation of ODC that had been induced in hepatoma tissue-culture (HTC) cells by refeeding with fresh medium. Furthermore the inhibitor inhibited the rapid degradation of ODC that had been induced by hypotonic shock. Interestingly, hypertonic shock was found to increase the proportion of ODC present as a complex with antizyme (the ratio of ODC–antizyme complex to total ODC). Cycloheximide, which partly inhibits rapid ODC degradation caused by hypertonic shock, also partly inhibited the increase in the ratio of ODC–antizyme complex to total ODC. These results suggest that a common ODC degradation pathway, namely the antizyme-dependent and 26 S proteasome-catalysed ODC degradation pathway, is also operating in intact cells for osmoregulated ODC degradation.

scholarly journals GhHUB2, a ubiquitin ligase, is involved in cotton fiber development via the ubiquitin–26S proteasome pathway

2018 ◽  
Vol 69 (21) ◽  
pp. 5059-5075 ◽  
Author(s):  
Hao Feng ◽  
Xin Li ◽  
Hong Chen ◽  
Jie Deng ◽  
Chaojun Zhang ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Cotton Fiber ◽  
Fiber Development ◽  
26S Proteasome ◽  
Cotton Fiber Development ◽  
Proteasome Pathway
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